Amblyopia is the most common cause of monocular visual impairment in children and young adults, affecting 3-5% people. Amblyopia is generally treated with patching or atropine therapy, however these treatments are not effective in adults and up to half of juvenile cases, often because of poor compliance, and cannot easily be personalized during therapy. These factors have led to recent interest in customized game-based binocular therapies that are administered in 3D entertainment systems. Typically functional endpoints are assessed with behavioral tasks that must be learned by the patient and interrupt the delivery of therapy. NeuroFieldz and Northeastern University have developed a new product NeuroDotVR combining a wireless NeuroDot sensor to measure Visual Evoked Potentials and Fields (VEPF) with a Virtual Reality headset powered by a smartphone to generate visual stimuli. In this Phase I STTR project, we propose to use the NeuroDotVR product with Swept-Contrast VEPF (SC-VEPF) as an objective, non-invasive endpoint to measure treatment response. SC-VEPF stimuli will be embedded within the therapeutic stimuli without requiring the patient to perform any task and enabling uninterrupted delivery of therapy. The project aims are: Specific Aim 1 Measurement of the Contrast Sensitivity Function with the SC-VEPF We will measure the SC-VEPF in the impaired and fellow eyes of 15 amblyopic adults and 15 amblyopic children by recording the VEPF amplitudes to filtered noise stimuli as a function of contrast. Noise stimuli will be presented independently to each eye using the SC-VEPF system. We will systematically vary the peak spatial frequency of the noise stimuli (1, 2, 4 or 8 cycles per degree) and contrast, and vary the temporal frequency from 1 to 15 Hz, and measure VEPF amplitude to estimate the contrast sensitivity function of each eye. We hypothesize that compared to the fellow eye, the amblyopic eye will have attenuated VEPF amplitudes, especially at high spatial frequencies, and that the magnitude of the inter-ocular difference will vary with temporal frequency. Specific Aim 2 Diagnostic SC-VEPF Embedded within Therapeutic Stimuli To minimize interruption of therapy, we propose to embed the diagnostic filtered noise stimuli (1 to 8 cycles per degree) within the therapeutic stimuli (Hollywood movies with broad spatio-temporal spectrum). To reduce contamination between the diagnostic and therapeutic stimuli, the therapeutic stimuli will be digitally notch-filtered with a spatio-temporal filter that removes all spatial and temporal frequencies within one octave of the test spatio-temporal frequency. SC-VEPF will be measured in the impaired and fellow eye of 15 amblyopic adults and 15 amblyopic children and behavioral estimates of contrast sensitivity will be collected with the same stimuli. We hypothesize that patients will not object to the diagnostic noise embedded in the therapy stimuli and that compared to the fellow eye, the amblyopic eye will have attenuated VEPF amplitudes and behaviorally-estimated contrast sensitivity, especially at high spatial frequencies.